The present invention relates to a picture quality compensating apparatus and method in a video signal recording/reproducing system, and particularly to a picture compensating apparatus and method for compensating degraded picture quality caused by damage to a control signal recorded on a video tape, during reproduction.
Generally, video cassette recorders (hereinafter referred to as a "VCR"), a laser players, and VCRS integrally formed within a camera (hereinafter referred to as a "camcorder," are typical examples of video signal recording/reproducing apparatus. Among these examples the VCR and camcorder use magnetic tape (video tape) as a recording medium, and the laser disc player uses an optical disc.
In a common helical scanning type VCR, the video tape has a video signal track for video signals, an audio track for audio signals, and a control track for control signals. Here, even though the control signal is able to prompt more effective reproduction by holding specific data such as a video index search system, the control signal is commonly utilized for controlling the phase of a capstan motor during reproduction. For example, 30 pulses are generated per second in an NTSC system, and 25 pulses per second in a PAL system, so that the control signal is used as reference data for controlling the phase of a capstan motor.
Accordingly, unless the control pulses defined by the above-mentioned broadcasting systems are not picked up from a control head during reproduction, a hunting phenomenon occurs, which degrades the picture.
Further, although the control signal may be compensated to prevent the degradation of the picture, the capstan is not perfectly controlled due to the phase difference between the compensating waveform and the original control signal. Especially, since the track itself is deviated once hunting occurs, the degrading of the picture may be prevented by compensating for the control pulse, but the tracking error remains uncompensated, so that an optimum picture cannot be displayed.